Three-dimensional sign



FIG. 1 is a perspective view of a three-dimensional sign according to afirst embodiment of our design; and,

FIG. 2 is a perspective view of a three-dimensional sign according to asecond embodiment of our design.

The broken lines illustrate portions of the three-dimensional sign thatform no part of the claimed design. The text in broken lines in FIG. 2also forms no part of the claimed design.

The three-dimensional sign is suitable to facilitate passenger trips forautonomous vehicles.

CLAIM The ornamental design for a three-dimensional sign, as shown anddescribed.